1. Field of the Invention
At least one embodiment of the invention relates to an implantable elongated electrode lead.
2. Description of the Related Art
Electrode leads of are connected, for example, to implantable cardiac stimulators such as cardiac pacemakers, cardioverters, defibrillators or the like, and may also serve as mapping catheters for diagnosis or neurostimulation.
Such electrode leads have the disadvantage that the electric lead thereof can heat up in a nuclear resonance tomograph because the alternating magnetic fields in the nuclear resonance tomograph induce notable electric currents in the electric conductor. For this reason, patients with cardiac pacemakers typically cannot be examined in a nuclear resonance tomograph, or only to a limited extent.
Typically, at least one stimulation electrode lead is connected to implantable cardiac pacemakers or defibrillators, which comprise a standardized electric connector on the proximal end thereof intended for connection to the cardiac pacemaker or defibrillator, and comprise one or more electrode poles on the distal end thereof intended for placement in the heart. Such an electrode pole is used to output electrical pulses, e.g. to the tissue (myocardium) of the heart, or to sense electric fields in order to allow sensing of an activity, such as cardiac activity, within the scope of so-called sensing.
For these purposes, electrode poles typically form electrically conductive surface sections of an electrode lead. Electrode poles are typically provided as ring electrodes in the form of a ring around the electrode lead or in the form of a tip electrode on the distal end of the electrode lead.
The electrode poles are connected in an electrically conductive manner by way of one or more electric supply leads to contacts of the electric connector of the electrode lead at the proximal end thereof. One or more electric supply leads which electrically connect one or more of the electrode poles to one or more of the contacts therefore extend between the contacts of the electric connector of the electrode leads at the proximal end thereof and the electrode poles at the distal end of the electrode lead.
Such supply leads contain electric leads required for the functions of the particular electrode lead and are therefore exposed to the risk that electric currents can be induced therein by external alternating magnetic fields, which can result, for example, in unwanted heating of the supply leads or the electrode poles connected thereto, or which can result in the output of corresponding currents by way of the electrode poles to surrounding tissue and, therefore, in heating of the surrounding tissue.